How to Clean Battery Terminals

Two Methods:Lead/Acid Battery or Car BatteryAlkaline Battery or Common Household Battery

Battery grime can cause current leak and shorten the life of your battery. Keeping your battery connections clean can not only help your battery live longer but can also save you money. Read below to learn how to clean a variety of battery terminals.

Method 1
Lead/Acid Battery or Car Battery

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    Access and assess your batteries. You do not need to remove the battery to assess it or to clean it. To simply access the battery, pop open the car hood and locate the battery. Check the general condition of your car battery. If your battery case has cracks you should replace the entire battery. If the battery appears fine continue to the next steps.
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    Assess the corrosion. Lift up, and to the sides, the plastic/rubber covers on top of the battery. This will reveal the terminal/clamp interface. Examine the battery cables and clamps for excess wear or corrosion. Corrosion appears as a white, ashy deposit around one or both battery posts. If the damage is extensive, you may want to completely replace the cables and clamps to avoid future problems. If however, the cables and clamps look good, just a little buildup, follow the instructions below on how to clean them.
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    Disconnect your car battery. Before starting you will need to disconnect the battery. To do this loosen the nuts on the clamps using a wrench. Once loosened remove the negative clamp, marked with a "-" first. It is very important the order. Only after the negative clamp is removed, remove the positive clamp, marked with a "+" [1].
    • The clamps may prove difficult to remove, especially if there is a lot of corrosion. You may need to use pliers to remove them. If you do need to use any metal tools, such as pliers, be careful not to touch the tool to the car frame (or anything else metal) and the battery while working. Doing so will short out the battery.
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    Make your cleaning agent. Combine 2–3 tablespoons (29.6–44.4 ml) of baking soda with a tablespoons or so of water. Stir to make a paste.
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    Apply the paste. Apply the baking soda paste to the battery connections. Be careful, although baking soda is generally safe, you should take care not to get it on other car components or on your self. Once the baking soda is applied, you will see it bubble and foam, as it reacts with the corrosion.
    • How you decide to apply this paste is up to you. You may rub it on with an old toothbrush, a damp rag, or even your gloved hand.
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    Scrape off deposits. If your battery terminals have heavy deposits you may need to scrape them off. An old butter knife works well for this. After you have removed the major deposits use a wire brush or steel wool to remove any remaining deposits.
    • There are special "battery post" and "battery clamp" brushes available at most auto parts stores, but these are not necessary. A general steel brush works fine.
    • It is best if you wear vinyl (dishwashing) gloves while cleaning the terminals, especially with steel wool, as you will be coming in direct contact with potentially caustic agents.
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    Rinse. When the foaming stops and there are no major deposits left to be scraped off. You need to rinse your connections. To do this, just use a little water. Be careful not to rinse the the baking soda paste into the battery vents, as the baking soda can neutralize the battery's acid and shorten the battery's life.
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    Dry. Wipe the terminals clean with a dry clean rag.
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    Prevent future corrosion. Add something hydrophobic, such as petroleum jelly (vaseline) or grease to the now cleaned terminals. This will help slow future corrosion.
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    Replace the clamps. Put on the positive clamp first, then the negative clamp. Use a wrench to tighten if needed. Once the clamps are on, replace the rubber or plastic shields covering the clamp/terminal junction.
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    Done.

Method 2
Alkaline Battery or Common Household Battery

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    Access and assess your batteries. How you access the batteries will depend on the device they are powering. In general you will need to open or remove the device's cover to access the battery cradle. Remove any old batteries. Assess these old batteries for cracks and leakage. Any leakage is likely potassium hydroxide, a strong base. If leakage is found proceed with caution and be sure to wear skin and eye protection, as potassium hydroxide is caustic.
    • You should never try to clean up any battery leakage with the following methods. The following baking soda cleaning method is just for any corrosion around the terminals, not for a leaking battery.
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    Assess the corrosion. Examine the now empty battery cradle's terminals and the battery for corrosion. Mild corrosion will appear as black spots, more severe corrosion appears as a white, ashy deposit around one or both battery posts or terminals. If you see corrosion follow the steps below to clean.
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    Clean with water. Use a damp soft cloth or cotton swab to remove any major corrosion deposits. Wear vinyl (dishwashing) gloves while cleaning any battery corrosion.
    • In some lucky cases the entire battery cradle may be removable from the electronic device. If this is the case you may soak the entire case in water or a diluted baking soda solution. However, in most cases you will have to patiently rub off the corrosion with a cotton swab, while the battery cradle remains in the device.
    • Take care not to touch with bare skin the white crusty buildup, as it is caustic.
    • Be careful not to get any water on your electronics when cleaning.
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    Clean with baking soda. Make your cleaning agent by combine 1 tablespoon (14.8 ml) of baking soda with a teaspoon or so of water. Stir to make a paste. Apply the baking soda paste to the battery connections using a cotton swab or small piece of cloth. Once the baking soda is applied, you may see it bubble and foam, as it reacts with the corrosion.
    • Be careful, although baking soda is generally safe, you should take care not to get it on other electronic components or your self.
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    Rinse. When the foaming stops and there are no major deposits left to be scraped out. You need to rinse your connections. To do this, use just a little water applied with a cotton swab. Be very careful not to get any water any electrical components.
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    Dry. Wipe the terminals clean with a dry clean rag.
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    Prevent future corrosion. Add something hydrophobic, such as petroleum jelly or grease to the now cleaned terminals. This will help slow future corrosion.
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    Put everything back. Put new batteries into the now clean battery cradle, and close up the case or put back on the cover.
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    Done.

Warnings

  • Be careful when using water around electronic components. If you feel you cannot clean the battery terminals while keeping your electronics dry. Do not attempt and bring your device in for professional repair.
  • Car batteries should be considered dangerous. Car batteries release hydrogen gas when charging or discharging and therefore they can be explosive. Keep open flame away and avoid any sparking while working around a car battery.
  • Corrosion around terminals should be considered caustic (it can burn you) be careful. Use gloves and eye protection.
  • Batteries contain strong acids or bases, both of which can burn your eyes and skin. Never try to open a battery.

Things You'll Need

Lead/Acid Battery or Car Battery

  • Clean rag
  • Water
  • Baking soda
  • Wire brush or steel wool
  • Wrench
  • Old butter knife or another tool suitable for scraping
  • Petroleum jelly

Alkaline Battery or Common Household Battery

  • An applicator: lint-free cloth or cotton swab
  • Water
  • Baking soda
  • Petroleum jelly

If you decide to use gloves for this project make sure to select ones that resist chemicals. Otherwise, if your skin comes into contact with corrosive chemicals, rinse hands under running water immediately. Follow current first aid guidelines.

Article Info

Categories: Maintenance and Repair